The present invention relates to a shelf engagement mechanism for use in shelf structures used in homes, offices, warehouses, and shops, among other places.
Conventionally, a shelf structure as shown in FIG. 14 is known. The shelf structure includes a plurality of vertically arranged shelves 1 and four supports 2 for supporting the shelves 1. Such a shelf structure is disclosed in, for example, Japanese Utility Model Application Laid-Open (kokai) No. 13575/1994. As shown in FIG. 15, the shelf structure includes shelves 1, supports 2, cylindrical joints 5, and taper sleeves 6. The shelf includes wire members 3 arranged in the form of a lattice, edge members 4, and edge-member reinforcement members 10. Each edge-member reinforcement member 10 extends along the corresponding edge member 4. Longitudinally intermediate portions of each edge-member reinforcement member 10 are connected to the corresponding edge member 4. An end of each edge-member reinforcement member 10 is connected to the corresponding cylindrical joint 5, which is provided at a corner of the corresponding shelf 1. Each taper sleeve 6 is attached to the corresponding support 2. The corresponding cylindrical joint 5 is fitted onto the taper sleeve 6, whereby the support 2 supports the shelf 1 at the corresponding corner. An inner surface of each cylindrical joint 5 and an outer surface of the corresponding taper sleeve 6 are tapered such that their diameters increase along a downward direction in FIG. 15, and the cylindrical joint 5 and the taper sleeve 6 are engaged together upon assembly.
However, the above-described conventional shelf structure has the following drawback. When two of the shelf structures are to be connected together such that adjacent shelves from the respective shelf structures are to be connected laterally in an aligned manner, additional supports or special joints must be prepared. In other words, the laterally aligned shelves of the respective ones of the shelf structures cannot share the same support unless special joints are provided.
Accordingly, when the above-described conventional shelf structures are to be connected with laterally adjacent shelves aligned with each other, additional supports, poles, or special joints must be employed, involving an increase in a number of component parts. For example, when hook-type joints are employed for connecting shelf structures, the resultant shelf structure has a poor appearance and involves a drawback in that strength against lateral vibration is deteriorated.
As described above, the conventional shelf structure does not allow shelves to be laterally connected in an aligned manner while sharing the same support, without the use of special joints. Thus, when shelves are connected laterally while sharing the same support without the use of special joints, the connected shelves must be at different levels. When a shelf structure is to be connected to an existing shelf structure by use of special joints in such a manner as to share the same support and to laterally align adjacent shelves into mutual alignment, an angle that the connected shelf structures form is limited to 180.degree. (linear connection) or 90.degree. (perpendicular connection, as in the case of installation in a corner of a room); i.e., the angle cannot be arbitrarily selected.
When, in order to assemble the conventional shelf structure, the cylindrical joints of the shelves are fitted to the corresponding supports, top or bottom ends of the supports must be inserted through the corresponding cylindrical joints, followed by movement of the cylindrical joints to predetermined positions on the supports. When the shelves are to be removed from the supports, they must be moved up or down to the ends of the supports and be removed sequentially. Accordingly, when a shelf is to be added to the assembled shelf structure, shelves located above or below an intended installation position of the shelf must be removed from the supports.